This invention relates generally to an apparatus for monitoring the position of a valve, more particularly an apparatus that delivers simultaneous visual and electrical signals corresponding to valve position.
Valve position monitors are important components of effective process control systems in industrial and laboratory settings. Valve position monitors enable the operator to determine the operational position of a fluid handling valve. Generally such valve position monitors transmit the position of a valve, such as whether the valve is completely open, completely closed, or some position therebetween. Monitoring systems have shown particular value in environments where access to valves is limited and physical inspections of each control valve are necessary to ascertain the operational position. Physical inspections are time consuming. Such inspections also unnecessarily expose operators to possibly dangerous and hazardous situations characteristic of certain industrial and laboratory environments.
Valve position monitoring systems allow for visual indication of valve position, in some environments at a distance of up to 150 feet. Valve position monitoring systems allowing for visual indication or the transmission of an electrical signal indicating valve position are well known in the art. Others have developed valve position monitors wherein both visual indication and transmitted electrical signals are provided. Exemplary of these valve position monitors with combined visual and electrical signals are U.S. Pat. Nos. 5,277,223; 5,223,822; and 6,135,147.
An object of this invention is to provide a valve position monitor that provides simultaneous visual and electrical signals of valve position, and that is easily adjustable.
A further object of this invention is to provide a method of monitoring the position of a valve by utilizing the valve position monitor described herein.
The present invention relates to a valve position monitor for delivering simultaneous visual and electrical signals of valve position and a method of monitoring valve position utilizing the valve position monitor. The valve position monitor comprises a body and at least one limit switch, the valve position monitor adapted to be connected to a valve actuator housing. The body in more detail comprises an output shaft, at least two trigger housings having at least one trigger that is detected by a limit switch, a biasing means, and a first means adapted to be secured to the valve actuator. Each trigger housing is capable of independent rotation and adjustment with respect to each other and with respect to the output shaft. In addition to a trigger, at least one of the two trigger housings has visual indicia thereon to provide a simultaneous visual signal. Any limit switch may be used provided that the limit switch detects the trigger and transmits an electrical signal representative of the valve position. Also, the present invention relates to a method of monitoring the position of a valve by utilizing the valve position monitor described herein.